Traders fixated on the Trump trade are about to get an idea of how far the president will go to stimulate the economy, after months speculating over the timing and size of his tax plan.

The S&P 500 Index jumped to an intraday high yesterday after the Wall Street Journal said Donald Trump urged aides to accelerate a tax plan cutting the corporate rate to 15 percent. The report, citing a person familiar with the matter, followed Trump’s tweet on Saturday that “Big TAX REFORM AND TAX REDUCTION will be announced’’ on April 26.

While budget director Mick Mulvaney said the White House will only offer “specific governing principles,’’ with no details until June, the reaction shows how sensitive investors remain to details of the program.

“The market this year has been baking in little hope of tax reform occurring,” Chris Senyek, a strategist at Wolfe Research LLC in New York, said